In spite of the extensive clinical resources devoted to management of hip disorders in young children, there is an almost total absence of quantitative data regarding the mechanical structural behavior of the juvenile proximal femur. We propose to conduct a detailed engineering investigation of load transmission through the proximal femurs of normal male children, aged one through seven years. Using fresh cadaveric hip specimens, laboratory data will first be collected to characterize the articular contact stress distributions and the cortical surface strains under three invitro static loading configurations representative of the range of normal walking gait. The proximal femurs will then be serially sectioned for sterometric analysis (including assessment of trabecular morphology), and later subsectioned into small samples for testing of the as yet poorly characterized elastic and viscoelastic mechanical properties of chondroepiphysis, growth plate, ossific nucleus, and immature metaphyseal and cortical bone tissues. The laboratory data will then be used as input to a three-dimensional finite element computational analysis of internal stress distributions. Based upon the results of recent two-dimensional pilot studies, we expect that the proposed analysis will reveal load transmission patterns which differ appreciably from those existing in the adult proximal femur.